有机硒催化的氧化脱氧在温和的条件下提供了酮和醛。反应使用过氧化氢和空气作为清洁氧化剂,并导致了无废料和无金属的脱保护方案,用于羰基保护策略以及绿色合成的酮和醛。通过控制实验以及硒77核磁共振(77 Se NMR)测试,已经研究了这种有趣的有机硒催化反应的机理。这种新颖的反应大大扩展了有机硒催化的应用范围。
Palladium-Catalyzed Annulation of Acyloximes with Arynes (or Alkynes): Synthesis of Phenanthridines and Isoquinolines
作者:Thibaud Gerfaud、Luc Neuville、Jieping Zhu
DOI:10.1002/anie.200804683
日期:2009.1.5
Intermolecular insertion: A palladium‐catalyzed domino aminopalladation/ CH functionalization sequence has been developed, and provides access to functionalized phenanthridines and isoquinolines (see scheme; Tf=triflate, TMS=trimethylsilyl, M.S.=molecular sieves). The use of butyronitrile as the solvent is determinant to the success of the domino process.
分子间插入:钯催化的多米诺aminopalladation / C ħ官能序列已被开发,并提供访问官能菲啶和异喹啉(参见方案; TF =三氟甲磺酸酯,TMS =三甲基甲硅烷,MS =分子筛)。丁腈作为溶剂的使用决定了多米诺骨牌工艺的成功。
Iron‐Enabled Utilization of Air as the Terminal Oxidant Leading to Aerobic Oxidative Deoximation by Organoselenium Catalysis
spectroscopy (XPS) analysis suggest that iron is crucial in the catalytic cycle, working to prohibit the deactivation of selenium catalyst through an iron‐catalyzed aerobic oxidation of lowvalent selenium species by air to the active high valent selenium species. Since air can be utilized as the terminal oxidant, this work may contribute to the advance of organoselenium catalysis.
The deoximation of a wide range of ketoximes and aldoximes to their corresponding carbonyl compounds with high yields has been achieved usinggrapheneoxide (GO) and sodium nitrite (NaNO2) as highly efficient catalysts and air as the green oxidant under mild conditions. The mechanism of deprotection and recycling use of catalyst were revealed in deep experiment. The carboxylic acid groups on the GO
We report realization of the first enantioselective Cope-type hydroamination of oximes for asymmetric nitrone synthesis. The ligand promoted asymmetriccyclopropene “hydronitronylation” process employs a Cu-based catalytic system and readily available starting materials, operates under mild conditions and displays broad scope and exceptionally high enantio- and diastereocontrol. Preliminary mechanistic
Organotellurium-catalyzed oxidative deoximation reactions using visible-light as the precise driving energy
作者:Xin Deng、Rongrong Qian、Hongwei Zhou、Lei Yu
DOI:10.1016/j.cclet.2020.09.012
日期:2021.3
Irradiated by visiblelight, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur undermildconditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visiblelight might be an
在可见光的照射下,可回收(PhTe)2催化的氧化脱氧反应可能在温和的条件下发生。与热反应相比,该方法使用了减少的催化剂负载量(1 mol%对2.5 mol%),但是在扩大的底物范围的情况下提高了产品收率。这项工作表明,对于有机碲催化的反应,可见光可能是比加热更为精确的驱动能量,因为可见光可以准确地破坏Te Te键,从而生成活性自由基催化中间体,而不会破坏易碎的取代基(例如杂环)的基板。使用O 2代替爆炸性H 2 O 2 从大规模应用的角度来看,作为氧化剂的氧化剂提供了更安全的反应条件。